Microtunnelling introduction to Ahmedabad 31 Dec 2020

Contractor ITD Cementation has selected Terratec micro TBM systems (MTBM) to complete about 6.5km of trunk-line sewer in the city of Ahmedabad in India. This is the first use of the microtunnelling technique in the city and will avoid the distruption of alternative open trench installation of the a new trunk sewer from Vadaj Circle to Mahalaxmi Char Rasta in the western part of the city.

Concrete pipes being jacking in behind the Terratec MTBM

The machine is supplied to install 1.4m diameter DN1400mm concrete pipes with the option of a later size increase to install DN1600 1.6m diameter pipes. The scope of the Terratec equipment supply includes the MTBM shields, main jacking stations, intermediate jacking stations, slurry transport and pipe lubrication systems, digital guidance systems and operator control cabins. Terratec also provided ITD Cementation with an on-site service package which includes the assistance of key engineers and MTBM operators.

The microtunnelling project has begun in the Vadaj area and will take about two years to complete with breakthrough of the first of many pipejack drives in early December. The machines are to bore through geological deposits composed of clay, stiff clay and sand. The MTBMs feature a cone crusher integrated into the cutterhead structure and laser guidance systems developed by Terratec.

Breakthrough of the 1.4m diameter MTBM at the end of the first drive

“As the leading TBM supplier in India, we continue to perform well with TBMs from the samller diameter microtunnelling project to larger diameter metro drives,” said Gulshan Gill, Managing Director of Terratec in India. “In the past 10 years, Terratec has supplied TBMs, MTBMs and rolling stock systems to several leading contractors including LNT, TATA, ITD, HCC, J.Kumar, Patel, Soma, Gulermak and Samsung. As a matter of fact, Terratec TBMs have completed more than 70km of tunnelling in India over the years, completing the drives in a timely and safe manner.”

The new sewer lines in Ahmedabad will improve wastewater management in the city and help manage stormwater flows and avoid frequent floods. Flow from existing lines will be diverted into the new trunk sewer for transfer to the treatment plant at Vasna. When complete, the new sewer will increase wastewater flow capacity by 550 million litres/day.